Resumen Los métodos tradicionales de clasificación de los asfaltos se basan en la penetración o viscosidad de estos, pero tienen como desventaja que se pueden clasificar diferentes tipos de asfaltos con el mismo grado, cuando en realidad tienen comportamientos diferentes. Además, no predicen el funcionamiento del pavimento ante las variaciones de carga y temperatura. Para solucionar estas limitaciones, surge el método de diseño Superpave, que, entre sus novedades, propone nuevas especificaciones para la clasificación de los asfaltos, en función de su grado de desempeño (PG, por sus siglas en inglés). El sistema PG se basa en la idea de que las propiedades de los asfaltos deben estar relacionadas con las condiciones bajo las cuales se está utilizando. Esto involucra condiciones climáticas esperadas, temperaturas del pavimento y condiciones de envejecimiento. El objetivo de este trabajo fue determinar los PG de los asfaltos en Cuba. Para esto, se emplean tres modelos de cálculo y las condiciones climáticas y geográ ficas de 52 estaciones meteorológicas. Se compararon los resultados obtenidos por los modelos empleados y se escogió el que mejor homogeneidad mostraba en los resultados. De esta forma, se determinaron las temperaturas extremas a las cuales será sometido el pavimento asfáltico. Como novedad para Cuba, permitió establecer un sistema único de clasificación para todos los asfaltos utilizados en el país y dos cla sificaciones: PG 64-6 y PG 64-0. Con estos resultados, se diseñó un mapa de zonifica ción de los PG en el país.

Abstract Traditional asphalt classification methods are based on their penetration or their viscosity. They have limitations as they can classify different types of asphalt with the same degree, when in fact they have different behaviors. Also, the performance of pavement in the face of variations in load and temperature is not predicted. To solve these limitations, the Superpave design method was created. Among its novelties, it proposes new specifications for the classification of asphalt, depending on their performance grade (PG). PG system is based on the idea that the properties of an asphalt binder should be related to the conditions under which it is being used. This involves expected climatic conditions, pavement temperature, as well as ageing conditions. The aim of this work is to determine the PG grade that asphalt in Cuba must have. For this, three calculation models and the climatic and geographic conditions of 52 meteorological stations were used. The results obtained by the models used were compared and the one with the best homogeneity in the results was selected. With these results a zoning map of PG grades in Cuba were designed.

This study was conducted with the objective of evaluating the use of concrete or hard-packed dirt floor in broiler houses. This experiment was carried out in two different phases. The following performance parameters were studied: live weight, feed intake, feed conversion ratio, and mortality. Litter moisture, pH and temperature were measured. Litter residual contamination after cleaning and disinfection was also evaluated. A dry bulb thermometer, a wet bulb thermometer, and a black bulb thermometer were placed inside each broiler house at bird height and outside the broiler house for data collection. Environmental data were collected at 3h intervals from 00:00 to 24:00 hours during weeks 4, 5, and 6 of the grow-out. Based on the collected data, air relative humidity (RH) was determined, after which wet bulb globe temperature (WBGT) and Radiant Heat Load (RHL) were calculated. There were no differences in live performance parameters. However, total mortality and sudden death were higher in birds raised on dirt floor. On days 0, 14 and 35, litter pH was higher in the dirt floor as compared to the concrete floor, but at the end of the grow-out, this difference disappeared. There was a cubic effect of bird age on litter moisture, which increased up to day 28, and then stabilized or decreased. Litter coliform contamination was higher at the end of the grow-out as compared to that found at housing, but it was not influenced by floor type. The general thermal comfort of broiler raised on dirt floor was similar to that of broilers raised on concrete floor.

Foi avaliado o progresso genético (PG) após oito ciclos de seleção recorrente para resistência à mancha-angular no feijoeiro e o ganho indireto para produtividade e tipo de grãos. A população-base (Ciclo-0) foi obtida do dialelo entre sete linhagens de grãos tipo carioca e dez fontes de resistência. Para obtenção do Ciclo-I foram intercruzadas as plantas S0 do Ciclo-0 mais resistentes. O mesmo procedimento foi adotado nos ciclos seguintes. O PG para resistência ao patógeno foi estimado pela média geral das progênies de cada ciclo em relação à testemunha 'Carioca MG' e, para produtividade, em relação à média das testemunhas ('Carioca MG' e 'Pérola'). Para tipo de grão foram utilizadas linhagens dos seis primeiros ciclos. Não foi detectado PG para resistência à mancha-angular. Contudo, o ganho indireto na produtividade foi de 2,3% e de 2,5% para tipo de grãos, valores semelhantes aos obtidos com a seleção direta para esses caracteres.

The genetic progress (GP) was evaluated after eight cycles of recurrent selection for resistance to angular leaf spot in common bean and indirect gain for yield and grain type. The base population (Cycle-0) was obtained from the diallel cross of seven lines with carioca grain and ten resistance sources. To obtain Cycle I, the most resistant S0 plants of Cycle 0 were intercrossed. The same procedure was adopted in the subsequent cycles. GP for resistance to the pathogen was estimated by the overall average of the progenies of each cycle in comparison with control Carioca MG and for productivity in comparison to the controls Carioca MG and Pérola. Lines of the first six cycles were used for grain type. No GP was detected for resistance to angular leaf spot. However, the indirect yield gain was 2.3% and 2.5% in the selection for grain type, with values similar to those obtained by direct selection for these traits.

Objetivou-se, neste trabalho, avaliar as modificações da poligalacturonase (PG) e da pectinametilesterase (PME) em morangos cultivados na região de Lavras, MG, e armazenados em temperatura ambiente. Foram utilizados morangos das cultivares 'Oso-grande', 'Toyorrinho' e 'Tudla'. Utilizou-se o delineamento inteiramente casualizado com 4 repetições, sendo os tratamentos arranjados em esquema fatorial (3X2), sendo 3 cultivares e 2 dias de análises (0 e 5 dias). A parcela experimental foi constituída por 10 frutos. Durante o armazenamento houve uma diminuição nos teores de pectina total e um aumento nos de pectina solúvel em todas as variedades analisadas. A atividade da PG e PME aumentaram com o período de armazenamento, independente da cultivar.

The objective of this research was to evaluate the modifications of the polygalacturonase (PG) and the pectinmethilesterase (PME) in strawberries cultivated in the region of Lavras, MG, and stored at room temperature. Strawberries of the research were used for plantation of 'Oso-grande', 'Toyorrinho' and 'Tudla'. The entirely randomized design with 4 replicates was used, being the treatments arranged in factorial (3x2), being 3 plantations and 2 days of analyses (0 and 5 days). The experimental parcel was consisted by 10 fruits. During the storage there was a reduction in the levels of total pectin and an increase in the ones of soluble pectin in all the analyzed varieties. With the period of storage the PG and PME activity grew, independent of the cultivar.

Avaliou-se a temperatura e a espessura de cama ideal para os sistemas de aquecimento elétrico (fibra de vidro e argamassa armada), em relação a temperatura ambiental, a partir de testes realizados em galpão para aves, na EMBRAPA-CNPSA. Os valores de temperatura em cada ponto determinado foram coletados de 5 em 5 minutos. O sistema permaneceu em funcionamento até a superfície superior de cama sobre a placa atingir o valor de 35ºC. O sistema mais adequado foi aquele em que a espessura da argamassa e a espessura da fibra de vidro foram 0,06m e 0,08m, respectivamente, com uma espessura de cama total, fora do círculo, de 0,11m.

The present study was conducted to evaluate the suitable temperature and thickness of the poultry litter related to the electric heating systems (glass fiber and armed mortar) and regarding the ambient temperature variations. Temperature values were obtained in specific places of the litter each 5 minutes. The system keeps working up to 35ºC at the top layer of litter. The suitable system was the one in which the armed mortar and glass fiber thickness were respectively, 0,06 and 0,08 m. In this system, the total thickness outside the brooding area could be maintained at 0,11 m.